Many systems aboard the ZR1 are monitored by the Electronic Control Module (ECM). Theoretically, when a monitored system moves out of a predetermined range, the SES light will come on. The SES light will also appear if an electrical short or open in a monitored circuit occurs. There are also several common reasons for this warning to appear.

On all year models, if the SES comes on during hard acceleration, then most probably a code 61, Secondary Throttle system error has occurred. Test you vacuum pump (located in the right front headlight cavity) by turning on both ignition and power keys (do not start the engine) and disconnecting the secondary vacuum connection coming from the pump. The pump should turn on immediately and run continuously. Place a finger over the open line and the pump should suck down and quit running. Check all other vacuum connections. Particular to the '93 model year, we have seen a tremendous amount of problems with the Exhaust Gas Recirculation (EGR) systems. This may also be compounded by a faulty PROM (Programmed Read Only Memory) calibration. There is an updated replacement PROM available from your dealer.

Note: When the SES is illuminated, both the cruise control and secondary throttle systems will become inoperative.

The information contained in this website is for general information purposes only. Whilst we endeavor to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from loss of data or profits arising out of or in connection with the use of this website.

Through this website there are links to other websites which are not under the control of the ZR-1 Net Registry. We have no control over the nature, content and availability of those sites. The inclusion of any links does not necessarily imply a recommendation or endorse the views expressed within them.